Sequential flow injection (FI) involves the temporary immobilization of functionalized microspheres as a renewable surface for (bio) chemical assays. We describe a microfabricated flow injection system that employs the ultrasonic flexural plate wave (FPW) device to acoustically capture microspheres from fluid flow. Microsphere capture is achieved by counteracting viscous drag force with radiation pressure generated from a standing acoustic field. The feasibility of acoustic trapping for FI is demonstrated with a bio-ligand assay of fluorescently labeled biotin conjugated to streptavidin coated microspheres.
Project end date: 08/15/03